Bulgaria's capital is becoming colder and darker after the country's natural gas supplies from Russia had been stopped on the morning of December 5, Bulgarian daily Gradski said.

By 11am on December 7, 28 schools in Sofia had requested permission to close as off the following day because of problems with heating and temperatures were dropping everywhere in the city, Gradski quoted deputy mayor Yordanka Fandukova as saying. For the entire country, a total of 80 schools had so far requested permission to close.

So far three schools in the city had suspended classes, Gradski said, at two schools emergency repairs were carried out.

Sofia mayor Boiko Borissov had ordered temperatures in schools and childcare facilities to be measured twice a day. If the temperatures would drop below 18 degrees, the facilities were to be temporarily closed.

Education minister Daniel Valchev issued the same order for public schools. If necessary, the school year would be restructured to make up for class time lost while schools are closed this winter, Gradski said.

Temperatures at the schools are measured by the heads of the schools, who compile and send reports by email to the municipality twice daily.

In a meeting in the evening of December 6, the crisis team at the Sofia municipality decided to reduce lighting in parks and of facades of buildings, and to stop the heating public transport.

If necessary, Toplofikatsiya Sofia, the company responsible for Sofia's heating and warm water, would switch to using residual fuel. According to Borissov, the Environment Ministry had already said it would not fine the company for doing so. Because of the sulphur in residual fuel, its used was allowed for only five days a year, Gradski said.